Fastening member and siding boards attachment structure using the fastening member

ABSTRACT

A fastening member  10  produced from a single steel sheet that is capable of stably supporting an exterior wall board and ensuring ventilation between the board and a building frame. The fastening member  10  comprises a left-side support portion  12 L and a right-side support portion  12 R on either side thereof that abut on the back surface of a board when fastened. In the intermediate region between the left-side and right-side support portions  12 L and  12 R, there are provided, from top to bottom, a substrate portion  11  that functions as a mount portion to be fixed to the building frame, a central support portion  12 C to be abutted against the back surface of a board when fastened, a locking portion  21  to be locked on the upper and lower edges of boards when fastened, and a lower support portion  12 U to be abutted against the back surface of a board when fastened.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a fastening member used for fasteningexterior wall boards such as ceramic siding boards to a building frame.The invention also relates to siding boards attachment structureemploying the fastening member.

2. Description of the Related Art

During the construction of an exterior wall of a building, a sidingboard 40 as shown in FIG. 5 that has an underlying rabetted portion 44and an overlying rabetted portion 42 at peripheral edges thereof, isfastened to a building frame using a fastening member. FIG. 6 shows afastening member 50 disclosed in JP Patent Publication (Kokai) No.2001-27031 A. The fastening member 50, which is formed by sheet metalwork, includes support portions 51 a, 51 b adapted to abut on a backsurface of an upper and a lower building board, respectively, whenfastened, a locking portion 52 formed by successively bending a centralportion of the support portion 51, a substrate portion 53 above thesupport portion 51 a, and a bend portion 54 at the lower edge of thesupport portion 51 b. When the metal fastening member 50 is fixed to thebuilding frame, the substrate portion 53 and the end of the bend portion54 constitute the mount portions via which the metal fastening member 50is mounted on the building frame.

During construction, the overlying rabetted portion 42 at the lower edgeof an upper board is locked on the locking portion 52, with the backsurface of the exterior wall abutting against the support portion 51 a.The underlying rabetted portion 44 at the upper edge of a lower board islocked on the locking portion 52, with the back surface of the boardabutting against the support portion 51 b. The fastening member 50further includes a depressed opening 61 formed in the support portion 51a that has such a depth as to reach the building frame and that helpsstabilize the mounting of the fastening member 50 to the building frame.When the boards have been fastened, a space is established between theback surface of the boards and the building frame, the spacecorresponding to the interval between the face of the substrate portion53 and the face of the support portion 51, so that ventilation can beensured.

JP Patent Publication (Kokai) No. 9-302889 A (1997) discloses afastening member 70 that is also formed by sheet metal work, as shown inFIG. 7. The fastening member 70 includes a substrate portion 71 thatconstitutes a mount portion that is fixed to the building frame, andsupport portions 72, 72 formed at either side edge of the substrateportion 71 such that they protrude forwardly while extendinglongitudinally. The fastening member further includes a locking portion73 formed laterally between the support portions 72, 72 on either side,with the end of the locking portion 73 located more forwardly than thesupport portions 72, 72. The locking portion 73 is formed by bending alower region of the substrate portion 71. The locking portion 73includes rise portions 75, 75 formed by bending either side of the endthereof upward, and a fall portion 76 formed by bending a center portionof the end thereof downward. The upper board is fastened by having theoverlying rabetted portion 42 at the lower edge thereof locked on therise portions 75, 75, with the back surface of the board abuttingagainst the support portions 72, 72. The lower board is fastened byhaving the underlying rabetted portion 44 at the upper edge thereoflocked on the fall portion 76, with the back surface of the boardsimilarly abutting against the support portions 72, 72. When the boardshave been fastened, a space is established between the back surface ofthe boards and the structural frame that corresponds to the height ofthe support portions 72, so that ventilation is ensured.

SUMMARY OF THE INVENTION

In the fastening member 50 shown in FIG. 6, since the locking portion 52is formed by laminating the steel sheet two fold, the fastening memberis rather heavy and requires much steel, resulting in higher cost.

In the fastening member 70 shown in FIG. 7, the locking portion 73 isformed of a single sheet and is therefore less heavy and less costly.However, since the locking portion 73 is extended from the substrateportion 71 that is the mount portion on the building frame, the lockingportion 73 of the fastening member 70 is longer than the locking portion52 of the fastening member 50 shown in FIG. 6, in which the lockingportion 52 is extended from the support portion 51. Thus, the strengthof the locking portion 73 is rather unreliable, particularly when aheavy, large-sized board is to be fastened.

Further, the fastening member 70 is designed to support the back surfaceof the board exclusively with the left and right support portions 72,72. Thus, when the adjacent portions of two laterally adjacent boardsare to be fastened with a single fastening member 70, the back surfaceof each board must be supported by one of the two, i.e., left and right,support portions 72, resulting in a fastening stability problem.

In view of the aforementioned problems of the prior art, it is an objectof the present invention to provide an improved fastening member formedof a single steel sheet that can be manufactured using a smaller amountof steel so that it is light and inexpensive, that is equipped with asufficiently strong locking portion, and that is capable of stablysupporting an board. It is another object of the invention to provide ahighly stable exterior wall structure that employs the aforementionedfastening member.

In one aspect, the invention provides a fastening member for boards,said fastening member comprising a left-side and a right-side supportportion on either side thereof, said support portions being adapted toabut on a back surface of an board when said board is fastened, saidfastening member comprising, in the intermediate region between saidleft-side and right-side support portions, from top to bottom:

-   -   a substrate portion that constitutes a mount portion to be fixed        to a building frame;    -   a central support portion that abuts on the back surface of a        board when fastened;    -   a locking portion extending from a lower end of said central        support portion and being adapted to be locked on an upper and a        lower edge of boards when fastened; and    -   a lower support portion that abuts on the back surface of a        board when fastened, wherein    -   said fastening member is formed from a single sheet of steel,        wherein said substrate portion is formed by depressing a portion        of an upper region of the steel sheet toward the back surface,        and said locking portion is formed by cutting a portion of a        lower region of the steel sheet and raising it toward the front        surface.

In the above fastening member, the locking portion is provided bycutting out a portion of the steel sheet as the material for the metalfastening member and then utilizing the cut-out steel sheet. Thus, thefastening member can be manufactured entirely from a single steel sheet,so that the weight and cost of the fastening member of the invention canbe reduced as compared with the conventional fastening member 50 shownin FIG. 6. Moreover, as the locking portion is extended from a supportportion, the length of the locking portion can be reduced as comparedwith the conventional fastening member 70 shown in FIG. 7, in which thelocking portion 73 is extended from the substrate portion 71. As aresult, the locking portion of the invention has a sufficient strengthdespite the fact that it is made from a single sheet.

Furthermore, as the back surface of the board is supported by theindividual support portions provided on either side of the fasteningmember and at the top and bottom of the locking portion, the backsurface of the board can be more reliably supported than it is supportedonly by the two support portions provided on either side of theconventional fastening member 70 shown in FIG. 7. In particular, whenfixing the lower ends of two boards where they are laterally adjoined toeach other, using a single fastening member, each board can be supportedat two locations, namely either one of the support portions on the sidesand the central support portion. Thus, the boards can be fastened in astable manner.

Preferably, the locking portion comprises at least one rise portion andat least one fall portion at an edge thereof. In this embodiment, thelocking portion can be formed by a simple bending process and yet theupper and lower ends of the board can be reliably locked by the thusformed locking portion.

Preferably, an area on either side of said fall portion near the loweredge thereof is bent toward the back surface of said fastening membersuch that the bent portions press against the board when fastened. Inthis embodiment, the board can be maintained in a position such that itis continuously pressed against the support portions, therebystabilizing the fastened state. Moreover, by forming the tip of the bentportion in such a shape that the tip cuts into the surface of the board,an additional fastening stability can be provided by the wedge effect.

Preferably, at least one of said right-side, left-side, and lowersupport portions comprises a collar portion extending from an externaledge thereof further outward, wherein said collar portion is located inthe same plane as that of said substrate portion. In this embodiment,the collar portion as well as the substrate portion is abutted againstthe building frame, so that the fastening member can be fixed to thebuilding frame more stably.

Preferably, a cut is provided in an upper edge of said substrate portionnear said left-side and right-side support portion. In this embodiment,should a strong wind pressure (negative pressure) act on an board thathas been fastened, the areas of the substrate portion near the cuts aretemporarily deformed to absorb the wind pressure (negative pressure),thereby preventing an excessive load from being put on the rabettedportion of the board that is locked on the locking portion. Thus, astable fastened condition can be maintained for a long time.

In another aspect, the invention provides siding boards attachmentstructure comprising a plurality of said fastening members that aremounted in multiple rows such that their substrate portions abut on afixing surface of a building frame, and a plurality of boards each witha rabetted portion provided at at least an upper edge and a lower edge,wherein said boards are fastened in multiple rows such that they havetheir back surfaces abutting on said left-side, right-side, central, andlower support portions of the fastening members, the rabetted portion atthe upper edge is locked on said locking portion of an upper fasteningmember, and the rabetted portion at the lower edge is locked on saidlocking portion of a lower fastening member.

In this exterior wall structure, as the fastening member is lightweightand less costly, construction cost can be reduced while achieving areliable fastened state. Furthermore, as a ventilation space is formedon the back surface of the boards that are fastened, the problem of dewcondensation, for example, can be prevented.

Thus, the fastening member of the invention is made from a single sheetand is therefore lightweight and low cost, and yet the fastening memberis capable of reliably supporting the board via the locking portion andsupport portions thereof. Thus, the fastened state of the board can bemaintained in a stable manner for a long time using the exterior wallstructure according to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention and many of the attendantadvantages thereof will be readily obtained as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings, wherein:

FIG. 1 is a perspective view of an embodiment of the fastening memberaccording to the invention.

FIG. 2 is a plan view of a steel sheet as the material of the fasteningmember shown in FIG. 1.

FIG. 3 is a perspective view of an board having been fastened to abuilding frame using the fastening member shown in FIG. 1.

FIG. 4 is a cross section taken along line IV-IV of FIG. 3.

FIG. 5 shows an example of an board.

FIG. 6 shows an example of the conventional fastening member.

FIG. 7 shows another example of the conventional fastening member.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the drawings, a fastening member according to anembodiment of the invention and siding boards attachment structureutilizing the fastening member are described. FIG. 1 is a perspectiveview of the embodiment of the fastening member of the invention. FIG. 3is a perspective view of the exterior wall structure utilizing thefastening member.

A fastening member 10 shown includes a left-side supporting portion 12Land a right-side supporting portion 12R on the sides thereof that willabut on the back surface of an exterior wall when fastened. Thefastening member 10 also includes, in the intermediate region betweenthe left- and right-side portions 12L and 12R, a substrate portion 11that is to be fixed to a building frame. Below the substrate portion 11,the intermediate region includes a central support portion 12C that willabut on the back surface of a board when fastened. Further below, thereare a locking portion 21 to be locked on the upper and lower edges ofboards when fastened, and then a lower-side support portion 12U thatwill abut on the back surface of a board when fastened. The supportportions 12L, 12R, 12C, 12U have the same height and are formed as acontinuous portion. These support portions 12L, 12R, 12C, 12U supportthe back surface of a board.

The fastening member 10 is formed by punching, drawing and bending asingle sheet of steel, such as a stainless steel plate or alloy platedsteel plate. FIG. 2 shows a steel plate 100 as the material for thefastening member 10. The steel plate 100 has a thickness of about 1.0mm, which is rather thick, such that the number of reinforcing ribs tobe provided in the fastening member 10 can be reduced. Numerals inparentheses shown in FIG. 2 indicate the corresponding parts of thefinished fastening member 10 of FIG. 1.

An example of the process of manufacturing the fastening member 10 willbe described below. First, the steel plate 100 (see FIG. 2), in whichfixing screw openings 31, nail openings 34, cuts 36, and a cut N arealready formed, is punched. The cut N is formed in a lower portion 100Bof the steel plate 100 roughly in the U shape as seen in a plan view.The area encircled by the cut N forms an extending portion 102 that willform the locking portion 21 of the fastening member 10 when theprocessing of the plate is finished. The extending portion 102 includesthree protruding portions 102 a, 102 b, and 102 c at the end thereofthat will form the rise portions 22 and fall portion 23 of the lockingportion 21 when the processing of the plate is finished.

The steel plate 100 is then drawn along the two-dot chain lines of FIG.2 such that the steel plate 100 is partly bulged to form the left-sidesupport portion 12L and the right-side support portion 12R on eitherside of the steel plate 100, the central support portion 12C at thelower region 100B, and the lower support portion 12U. As a result, inthe central portion 101 in the upper region 100A of the steel plate 100,there is formed the substrate portion 11 that is depressed toward theback surface by about several millimeters. Further, a collar portion 13is formed along the outer edge portions of the left-side, right-side,and lower support portions 12L, 12R, and 12U. During the aforementioneddrawing process, a raised portion 32 within which nail openings 34 areto be disposed and reinforcing ribs 35 are simultaneously formed.

Then, the extending portion 102 that is formed in the lower region 100Bof the steel plate 100 in advance is bent at a right angle along theupper side thereof (dashed line L1 in FIG. 2) towards the front surface.Further, the left and right protruding portions 102 a and 102 c at theend of the extending portion 102 are bent diagonally upward along dashedlines L2 a and L2 c of FIG. 2 such that the rise portions 22, 22 areformed. The protruding portion 102 b at the center of the end of theextending portion 102 is bent diagonally downward along a dashed line L2b of FIG. 2 such that the fall portion 23 is formed. The locking portion21 is thus formed in a shape that conforms to the rabetted portions ofthe board that is fastened. The edge portions on either side of the endof the fall portion 21 are further bent toward the back surface alongdashed lines L3, L3 shown in FIG. 2 such that bent portions 23 a, 23 aare formed.

While the fastening member 10 is completed by the above-describedbending process, the fastening member of the invention is not limited tothe above-described embodiment. For example, the collar portion 13 andthe cuts 36 may be omitted.

Hereafter siding boards attachment structure utilizing theabove-described fastening member 10 will be described. FIG. 3 shows anboard 40 as shown in FIG. 5 that has been fastened using the fasteningmember 10. FIG. 4 shows a cross section taken along line IV-IV of FIG.3. In the illustrated example, the fastening member 10 is fixed, via awaterproof paper P and a furring strip 2, to a building frame 1 by anail 3 passed through the nail opening 34 formed in the substrateportion 11. Specifically, after the fastening member 10 is positionedsuch that the locking portion 21 externally fits on the underlyingrabetted portion 44 at the upper edge of a lower board 40A that islocated at a lower position, the fastening member 10 is fixed byutilizing the nail opening 34. The nail opening 34 is formed in an upperslanted surface 33 of the raised portion 32. Thus, the fastening member10 is pushed downward as a whole as the nail is driven, so that thefastening member 10 can be stably fixed. Furthermore, the board 40A ispressed against the building frame 1 by the bent portions 23 a, 23 aformed on either side of the fall portion 23. The back surface of theboard is therefore pressed against the support portions 12L, 12R, and12U in an air-tight manner, and the lateral movement of the board isprevented by the resultant wedge action, so that the fastening membercan be more stably fixed. The fastening member 10 can be fixedalternatively by a bis utilizing the screw openings 31.

Near the root of the underlying rabetted portion 44 at the upper edge ofthe lower board 40A, there is placed a caulking material in advance forleakage control purposes. After a required number of the fasteningmembers 10 are fixed horizontally at predetermined intervals, a requirednumber of upper boards 40B, which are located at a higher position, aredisposed laterally such that the overlying rabetted portions 42 at thelower edges thereof internally fit on the locking portions 22 of thefastening members 10. Thereafter, additional fastening members 10 aremounted on the underlying rabetted portions 44 of the upper edge of theupper boards 40B, which are now lower boards, in a similar manner, andare then fixed by nails. The same process is repeated for a requirednumber of rows, thereby completing the exterior wall structure of theinvention.

In the above-described exterior wall structure, the board 40 can bestably supported by the locking portion 11 and the individual supportportions 12L, 12R, 12C, and 12U of the fastening member 10. Between theback surface of the board 40 and the furring strip 2, there is formed aspace S by the support portions 12L, 12R, 12C, and 12U of the fasteningmember 10 that corresponds to the height of the support portions. As aresult, good ventilation can be obtained on the back surface of theboard, so that the problem of dew condensation, for example, can beprevented. In accordance with the exterior wall structure of theinvention, the fastening member is lightweight and yet has an excellentmechanical strength, so that it can maintain the fastened condition fora long time in a stable manner. Moreover, in cases where the cuts 36 areprovided in the substrate portion 11, as in the fastening member 10 inthe above embodiment, areas near the cuts 36 would be deformed if astrong wind pressure (negative pressure) acted on the board, therebyreducing the load that is put on the rabetted portion of the board 40locked on the locking portion 21.

1. A fastening member for an exterior wall board, said fastening membercomprising a left-side and a right-side support portion on either sidethereof, said support portions being adapted to abut on a back surfaceof a board when said board is fastened, said fastening membercomprising, in the intermediate region between said left-side andright-side support portions, from top to bottom: a substrate portionthat constitutes a mount portion to be fixed to a building frame; acentral support portion that abuts on the back surface of the board whenfastened; a locking portion extending from a lower edge of said centralsupport portion and being adapted to be locked on an upper and a loweredge of the board when fastened; and a lower support portion that abutson the back surface of the board when fastened, wherein said fasteningmember is formed from a single sheet of steel, wherein said substrateportion is formed by depressing a portion of an upper region of thesteel sheet toward the back surface, and said locking portion is formedby cutting a portion of a lower region of the steel sheet and raising ittoward the front surface.
 2. The fastening member according to claim 1,wherein said locking portion comprises at least one rise portion and atleast one fall portion at an edge thereof.
 3. The fastening memberaccording to claim 2, wherein an area on either side of said fallportion near the lower edge thereof is bent toward the back surface ofsaid fastening member such that the bent portions press against theboard when fastened.
 4. The fastening member according to claim 1,wherein at least one of said right-side, left-side, and lower supportportions comprises a collar portion extending from an external edgethereof further outward, wherein said collar portion is located in thesame plane as that of said substrate portion.
 5. The fastening memberaccording to claim 1, wherein a cut is provided in an upper edge of saidsubstrate portion near said left-side and right-side support portion. 6.An exterior-wall structure comprising a plurality of said fasteningmembers according to claim 1 that are mounted in multiple rows such thattheir substrate portions abut on a fixing surface of a building frame,and a plurality of boards each with a rabetted portion provided at atleast an upper edge and a lower edge, wherein said boards are fastenedin multiple rows such that they have their back surfaces abutting onsaid left-side, right-side, central, and lower support portions of thefastening members, the rabetted portion at the upper edge is locked onsaid locking portion of an upper fastening member, and the rabettedportion at the lower edge is locked on said locking portion of a lowerfastening member.